Spring latch for electrical connector



May 19, 1970 H. E. HENSCHEN ETAL 3,513,433

SPRING LATCH FOR ELECTRICAL CONNECTOR I Filed March 25, 1966 United States Patent SPRING LATCH FOR ELECTRICAL CONNECTOR Homer Ernst Hens'chen, Carlisle, and William Vito Panza,

Harrisburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Mar. 25, 1966, Ser. No. 537,424 Int. Cl. H01r 13/42 US. Cl. 339-217 13 Claims This invention relates to the art of spring latch devices and more particularly to a means for latching an electrical connector element in a housing member.

It is known to provide an electrical connector element with a spring latch device in order to maintian the connector element latched within an opening or passageway of a mounting or housing means. The free end of the spring latch device generally is disposed in a recess of the opening or passageway, abuts against the shoulder thereof, or engages a latching surface of a mounting means. This is the case especially in conjunction with small electrical connector elements such as disclosed in US. Pat. Nos. 2,682,038; 2,689,337; 2,741,750; 2,779,007; and 3,011,143, which are disposed in a mounting or housing means such as an insulating body, insulating block, vacuum tube socket, and plugboard panel respectively.

The spring latch device is generally formed during the stamping and formation of the connector element and thereby extends outwardly from the plane of the material to which it is integrally anchored. After the connector element has been formed 'it is then inserted within an opening or passageway in the mounting or housing means. This opening or passageway is just slightly larger than the part of the connector element to be disposed therein. As a result the spring latch device is pushed inwardly toward the axis of the connector element during the insertion thereof within the opening or passageway until the connector element is fully inserted into position; then the spring latch device springs outwardly thereby engaging the latching surface to latch the connector element in position.

It has been found that upon inserting the connectorelement within the opening or passageway to its latch position the spring latch device is substantially filattened and stress is'concentrated at the point of connection of the spring latch device to the body of the connector element thereby causing the point of connection to become weakened so that the spring latch device does not assume its original position. This could result in the spring latch device failing to perform its intended latching function. Moreover,upon a force being applied to the connector element or conductor means connected thereto in a direction opposite to the direction of insertion the weakened latch device could break away from the body. 3

Small electrical connector elements are frequently handled in such a manner that damage is likely to occur to any parts of the element which extend outwardly from the overall, confines of the connector. This is a frequent problemin the case of lances since these lances must necessarily extend outwardly from the confines of the connector. The extending lance may be damaged either by bending the free end of the lance to a position wherein the lance will not properly engage within a housing or the lance may be forced inwardly into the connector beyond the elastic limit of the lance whereby the lance cannot be restored to its original, position.

It is therefore an object of the present invention to provide a spring latch means on an electrical connector element which retains its resilient characteristics after the connector element has been inserted into position so that the spring latch means performs its intended latching function without failure thereof.

A further object of the present invention is the pro- 3,513,438 Patented May 19, 1970 ice vision of a spring latch means in a connector element which is easy to form during the forming process of the connector element and which retains its resilient characteristics throughout the life expectancy of the connector element and of the equipment associated therewith.

A still further object of the invention is to provide a spring latch means which is so disposed relative to an electrical connector element such that possible damage to the spring latch during handling of the connector is reduced to a minimum.

Another object of the present invention is to provide a spring latch which allows for increased mating length between the connector carrying the latch and a mating connector element.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purpose of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in' various forms, each as may be best suited to the conditions of a particular use.

In the drawings, in which like reference numerals refer to like parts:

FIG. 1 is a perspective view of a connector element made in accordance with the teachings of the present invention;

FIG. 2 is a side elevational view partly in section showing the connector element of FIG. 1 and its associated insulated housing; and

FIG. 3 shows the connector and housing of FIG. 2 in their assembled position.

The present invention will be described in conjunction with a conventional connector element and it is to be understood that the principles of the present invention could be utilized in conjunction with many other connector elements to be secured within a housing or mounting means.

Turning now to the drawings, there is shown in FIG. 1 a connector element C having a ferrule portion F in which a conductor means CM is secured by cold forging or crimping techniques disclosed in US. Pat. No. 2,600,- 012. Of course conductor means CM could be secured to the connector element in any other well known manner.

Connector element C also includes a body portion B which provides the electrical engagement with another connector element (not shown). Connector element C is preferably formed by shaping a sheet metal blank or strip of a suitable electrically conductive material such as brass, bronze or other alloy, the metal being sufficiently hard and resilient in order to provide excellent spring quality thereto as well as being malleable to permit the cold forging or crimping techniques mentioned above.

The particular connector element shown in the drawings is commonly referred to as a pin and will mate within a socket member to form an effective electrical connection. The body portion B of the connector element C is of cylindrical or tubular configuration and has a nose portion N which is generally rounded to provide for easy entrance of the connector element into its mating socket.

Turning now to FIG. 2 there is seen an insulating housing H within which connector element C will be inserted. Housing H has a longitudinal passageway for receiving element C, the said passageway comprising a series of stepped diameters. The central portion 10 of the passageway has a diameter slightly larger than the diameter of body portion B of the connector element C. On either side of portion 10 there are enlarged diameter sections .12 and 14 with the section 12 having a conically shaped entrance surface 16 providing for easy entrance of connector element C.

The connector element has an aperture 18 formed in its upper surface. A lance or spring latch means S is stamped out from body portion B along a surface diametrically opposed to the surface containing aperture 18. Lance S extends for a short distance from its point of attachment along a path generally parallel to the longitudinal extent of the connector element. The lance is then formed with a gradual radius and is bent inwardly to pass directly through the interior portion of body B and with the free end of the lance passing through the aperture 18 and being disposed externally of the body portion B. A pair of stops 22 are formed at the trailing edge of body portion B, these stops serving to limit the movement of connector element C into the housing As seen in FIG. 3 the connector element is seated within housing H with the spring latch or lance S being disposed within section 14 of the passageway of housing H and with the stop members 22 being disposed within section 12 of the passageway. By this configuration the element is prevented from movement in either direction within the passageway. Obviously, during entry of the connector element into the housing from left to right as seen in FIG. 3, the spring latch S will be cammed downwardly as it passes through section of the passageway and will then spring outwardly to its final position as it moves into section 14.-

Lance S may be of flat rectangular cross section. However, it is preferred that the lance be slightly arcuate in cross section for increasing the strength of the lance while detracting only slightly from its spring characteristics. It can be seen from the drawings that by bringing the lance S through the body portion B and through the aperture 18 on the opposite side of the body portion from which the lance is attached there is littie or no possibility of the lance being damaged by accidental compression of the lance during handling. The body portion B in effect acts as a shield around the lance and prevents the lance from being stressed beyond its elastic limit. Further, since only a small portion of the lance extends outside of body portion B there is little opportunity for the lance to be accidentally bent in a direction towards the nose N of the connector element. This condition is also protected against by reason of the stops 22 being preferably in alignment with the lance S.

A further advantage of the lance of the instant invention lies in the fact that the lance is substantially longer than the lances of the prior art designs wherein the lance would be bent directly outward of the body portion B rather than through the body portion. This extra length of lance aids in achieving better spring characteristics for the lance. Additionally, a longer lance allows for low insertion forces: that is the amount of force necessary to insert the connector element C within the housing H. Due to the length of the lance it is compressed more easily than a conventional lance and therefore there is required less force to properly seat the connector.

Due to the lance configuration of the present invention the mating length between the connector element C and its mating socket is indicated in FIG. 2 as the distance X. If the lance S were deflected downwardly, as seen in FIG. 2, in the conventional manner rather than upwardly through the connector, the mating length would be the distance indicated in FIG. 2 as Y. Therefore, it can be seen that the lance design of the present invention allows for a substantial increase in mating length between the pin and its associated socket and therefore greatly enhances the electrical characteristics of the connection.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the 4 scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

What is claimed is:

A connector element adapted to be received in a housing, said connector having an elongated hollow body having a forward portion and a rearward portion, an aperture disposed in a first side of said body and having a forward edge, said aperture being located between said forward and rearward portions, and a lance struck from said body along a second side opposite to said first side and secured to the forward portion of said body, said lance being bent inwardly from said second side and extending through said aperture in said first side, said aperture being of sufficient size to permit rearward flexing of said lance to a stressed position whereat the free end of said lance is substantially within the periphery of said hollow body, whereby upon insertion of the forward portion of said connector element into said housing said lance will be deflected by said housing to said stressed position and whereby upon further insertion said lance will be released outwardly of said body to a position of cooperation with a depending surface of said housing to thereby prevent withdrawal of said connector element from said housing, said lance being limited in its out wardly released position by the forward edge of said aperture.

2. A connector element as set forth in claim 1 further including stop means extending from said rearward portion for cooperation with said housing to limit movement of said connector element into said housing.

3. A connector element as set forth in claim 2 wherein said stop means comprises a pair of upturned ears located at the extreme end of said rearward portion.

4. A connector element as set forth in claim 1 wherein said lance slopes generally rearwardly front its point of attachment along said second side of said body.

5. A connector element as set :forth in claim 1 wherein said lance is of substantially arcuate cross-section.

6. A connector element adapted to be received in a housing, said connector having an elongated hollow body having a forward portion and a rearward portion, an aperture disposed in a first side of said body and having a forward edge, said aperture being located between said forward and rearward portions, and a lance struck from said body along a second side opposite to said first side, said lance being bent inwardly from said second side and extending through said aperture in said first side, said aperture being of suflicient size to permit rearward flexing of said lance to a stressed position whereat the free end of said lance is substantially within the periphery of said hollow body, whereby upon insertion of the forward portion of said connector element into said housing said lance will be deflected by said housing to said stressed position and whereby upon further insertion said lance will be released outwardly of said body to a position of cooperation with a depending surface of said housing to thereby prevent withdrawal of said connector element from said housing, said lance being limited in its outwardly released position by the forward edge of said aperture.

' 7. In an electrical connector, the combination comprising a terminal block having an open ended socket provided with radially inwardly extending shoulder means, an elongate electrical terminal inserted axially within the socket and having a hollow portion, saidtervrninal having a forward end adapted to be electrically connected with another terminal and a rear end to which a wire is adapted to be connected, the hollow portion of said terminal having a tab struck inwardly from one side thereof and an aperture on the opposite side thereof through which the free end of the tab extends, said aper= ture being axially offset substantially from the portion of the tab connected with said opposite side so that the tab extends across the hollow interior of the terminal at an acute angle to the longitudinal axis of the terminal with the projecting end of the tab engageable with the shoulder means on the terminal block to limit axial movement of the terminal in said socket in the direction of said rear end, said tab being flexible radially inwardly in the manner of a leaf spring through said aperture to clear said shoulder means and thereby permit axial withdrawal of the terminal from said socket rear end foremost, said aperture having two sides and having an end which is disposed closely adjacent the projecting portion of the tab on the forward side thereof to limit the extent of flexing of the tab in a radially outward direction through said aperture.

8. An electrical terminal of the type adapted to be inserted within a socket of a terminal block and having an elongate body with a forward end and a rear end, said body comprising a hollow portion having an opening through one side thereof and a tab struck inwardly from the opposite side thereof, said tab traversing the interior of said hollow portion and projecting through said opening at its free end, said tab being adapted to engage shoulder means on the terminal block to limit movement of the terminal in the socket in the direction of said rear end, the projecting portion of the tab being axially offset substantially from the portion of the tab connected with said opposite side of said hollow portion, said opening having sufficient axial extent in a direction rearwardly of the projecting portion of the tab to permit flexing of the tab radially inwardly through said opening in the manner of a leaf spring, said opening having two sides and having one end located closely adjacent the projecting portion of the tab on the forward side thereof to limit flexing of the tab in a direction toward the forward end of the terminal.

9. An electrical terminal as set forth in claim 8 wherein said tab traverses the interior of the hollow portion at an acute angle to the axis of the hollow portion.

10. An electrical terminal as set forth in claim 9, wherein the tab is inclined to the axis of the hollow portion at an angle of not greater than about 45.

11. An electrical terminal as set forth in claim 8, wherein the hollow portion is formed from a sheet metal which is at least slightly resilient.

12. An electrical terminal as set forth in claim 8, wherein the projecting portion of the tab is offset axially from the portion of the tab connected with said opposite side a distance equal to at least the transverse dimension of said hollow portion.

13. The combination set forth in claim 7 including means on said terminal engageable with said second shoulder means to limit axial movement of the terminal in the socket in the direction of said forward end.

References Cited UNITED STATES PATENTS 2,689,337 9/1954 Burtt et a1 339--217 2,779,007 1/ 1957 Cunningham 339217 X 3,059,213 10/ 1962 Lalonde 339217 X 3,215,975 11/1965 lKinkaid 339--217 X MARVIN A. CHAMPION, Primary Examiner P. A. CLIFFORD, Assistant Examiner U.S. CL X.R. 339-213 

1. A CONNECTOR ELEMENT ADAPTED TO BE RECEIVED IN A HOUSING, SAID CONNECTOR HAVING AN ELONGATED HOLLOW BODY HAVING A FORWARD PORTION AND A REARWARD PORTION, AN APERTURE DISPOSED IN A FIRST SIDE OF SAID BODY AND HAVING A FORWARD EDGE, SAID APERTURE BEING LOCATED BETWEEN SAID FORWARD AND REARWARD PORTIONS, AND A LANCE STRUCK FROM SAID BODY ALONG A SECOND SIDE OPPOSITE TO SAID FIRST SIDE AND SECURED TO THE FORWARD PORTION OF SAID BODY, SAID LANCE BEING BENT INWARDLY FROM SAID SECOND SIDE AND EXTENDING THROUGH SAID APERTURE IN SAID FIRST SIDE, SAID APERTURE BEING OF SUFFICIENT SIZE TO PERMIT REARWARD FLEXING OF SAID LANCE TO A STRESSED POSITION WHEREAT THE FREE END OF SAID LANCE IS SUBSTANTIALLY WITHIN THE PERIPHERY OF SAID HOLLOW BODY, WHEREBY UPON INSERTION OF THE FORWARD PORTION OF SAID CONNECTOR ELEMENT INTO SAID HOUSING SAID 